Electromagnetic coupling



Dec. 30, 1930. B. WITTKUHNS 1,737,225

ELECTROMAGNETIC COUPLING Filed April 20. 1927 jjnezzop. ,Bfll/QOWifikuhm; Z his 0722 :7 I y 11mm) mama-nee. 30,. 1230 f1 fomTEo, sr TesPATENT", OFFICE? ammo wn-rxunns, or NEW Yonx N. 1., nssrenon no was manuAeNn'r-wnax e. I. n. a. msmscn srnzmrrnmx. run. mnxtmonaennr-arrannm orEISENAOH, GERMANY I mncmonaennrro oourLmG 1 Application am (April 20,1927, sci-m K011815352, a m german' m 20, 1926.

My invention relates to electromagnetically operated friction couplingsor clutches, more particularly'to the type of disk clutches in whichthe. friction members consist of two sets of annular disks or rings"which are so united with their corresponding clutch parts, that, whilethey are capable of'arelative axial shift relative to each-other, theycannot undergo relative rotative circumferential displacement. Thefriction elements of both groups are so coordinated axially that afriction member of one group alternates with a friction member of theother group.

In the usual clutches of this type, the coupling member is fixedlyconnected w1th one shaft and carries the exciting windings andthus formsthe ma et body proper of the magnetic system 0 the clutch, in additionwith its associated friction members. The armature or keeper coactingtherewith is disposed inside the other couphng member which usually hasthe shape of a bell-shaped hollow I housing and carries the other set offr ction through the switching on of the exciting curcompression of thefriction members- As a.

' members andis fixedly united with the other shaft. In engagingclutches of this type rent, the armature of the magnet body is attractedto the exciting windings and causes result the latter are caused toengage frictionally, and this causes one of the clutch members to befrictionally enga ed to the other clutch member thereby estab ishing adriving coupling of the two shafts.

' In order to cause instantaneous release and disengagement of theengaged friction members, when desired, it has heretofore been thecustom in friction couplings of this type to provide thrust springsbetween the armature and the bell-shaped housing, whereby, as soon asthe magnetic force is dissipated, the armature is forced away from themagnet body or core in the direction of the bell-shaped body with theresult that the armature is released from the friction engagement. Whenre-engaging the clutch, these springs are tensioned again byaction ofthe magnetic pull, and this tension, which is preserved during theentire period of magnetic engagement of the clutch,

exercises aperm'anentload upon the otherclutch member. This lead or pullmust be compensated by.the use of special axial thrust springs, of thecompression type, produce no action at all upon the other clutch member.

. Their action occurs exclusively between the.

armature and the-magnet body which, when .the clutch is in the engagedposition, constitute a single assembly or unit. Hence, transfer of axialtraction or compression forces toward the assembly or closed systemcomprising the magnet body and the armature, is thus precluded, anddistinct axial thrust bearings for the other clutch member or the shaft.cfi'rying or supporting the same are dispens a e.

In the drawing the single figure there shown discloses, by way ofexample, a partially sectioned improved clutch, the upper halfthereofjoeing a vertical axial section, and the lower half insideelevation. Upon the inner end of one of the shafts- 1 to be coupled,there is fixedly keyed by a key, 1 the'magnet body 3 carrying. the ex{citing winding 2. The magnet body is provided in the usual manneroutside of the magnet winding 2 with a disk-shaped shell icarrying acylindrical ange 3', the outer face of which is furnishe with acomparatively large number of longitudinal ribs 5. The said outer facecarries one set of friction members consisting of annular disks 6. Theinner-edge of each disk is provided with recesses or notchescorresponding to the ribs" 5 of the body 3, the said. disks being thusguidedon the body 3 by the aid of said ribs 5 and the interveningrecesses so that the disks are capable of movement in axial directionbut not circumferentially with reference tothe magnet body 3. k

' The friction members or annular disks l of the other group are carriedby the cylin- 5 drical flange 8 of the second clutch member 9 carried bythe other shaft 10. The inner side of the flange 8 is also furnishedwith ribs 8' extending in axial direction, the members aid of a, sleeve'orbushing12, is guided upon the shaft .1 insuch a manner that it iscapable of displacement in axial direction upon the shaft. Rotation ofthe armature 11 with reference to shaftl and consequently with referencet0 the magnet body.3 is 'revented by a plurality of bolts 13.screwedinto the latter,

' said bolts passing through countersunk bores 13 of armature 11and'being furnished with b nuts at their extreme en'ds which serve asstops to limit movement of the armature 11 away from the body 3. Theparts of the bolts 13 adjacent to the magnet body 3 are surrounded bycoil springs 14 accommodated in suitable recesses 15 of the magnet body3. The said springs bear with one of their ends against the bottoms ofthe bores 15, while at the other end they bear against the armature 11,and they thus tend to push the latter away from the magnet body.

When switching on the exciting current which is supplied to the winding2 in the us- V ual manner through slip rings 16, the armabody 9 'sionforces are exerted ture 11, with incidental compression of springs 14,is attracted and forced against 7, by means of an annular washer 17placed between the armature 11 and the first ring 6 with the result thatthe disks are Caused to enter into frictional engagement with eachother. Thus the coupling of parts 3 and',9 and thereby of the two shafts1 and-10 is accomplished. During the movement of the armature toward themagnet body ber 9. All of the motions occurring during the clutchinitiating process, as well as such other liinetic actions as areassociated therewith, occur exclusively inside the system comprising-themagnet body 3 and the armature 11. The transmission of the torque occursexclusively from the magnet body 3 through the two sets of .disks 6, 7to the belleshaped and thencedirectly to the shaft 10.

I claim as my invention: 1. In combination, a pair of shafts; acupshaped clutch member on one shaft; an electure having 3, no pull orcompresupon the clutch memtromagnetic body mounted fast on the 0th shaftand received in said member and ha ing a hub portion provided withinward] opening shouldered longitudinal bores; fri tion membersalternately secured to sai body and clutch member respectively; a dis]shaped armature in the clutch member b1 tween the clutch member and themagm body and adapted, when attracted, to pre: the friction memberstogether; said arm: bolt holes alined with said bOI't and havingcountersunk ends adjacent to tt. clutch member; bolts passed through saiholes and bores and screwed into the magm body; springs on said boltscompressed b1 tween the armature and the shoulders of th bores to pressthe armature from the magm body; and nuts on the ends of the bolts i saicountersunk ends to limit movement 0 the disk toward the clutch member.v

2. The combination in a shaft clutch, con prising, with a pair ofshafts, an enclosin clutch member onone shaft; an electromag netic bodyon the other shaft; a plurality o superposed friction members; one group0 said friction members being secured to sai ody, an alternate group offriction member secured to said enclosing clutch member; friction memberpressing armature movabl located between said enclosing clutch mem berand the magnet body and adapted to b attracted by said magnet body toclose th friction members and means entirely en closed within saidenclosing clutch membe for permitting the friction members to sepa ratewhen the armature is released by th magnet body, said separating meansacting immediately between said magnet body am said armature in oppositedirections anl upon the armature and the body only.

3. The combination in a shaft clutch, com prising, with a pair ofshafts, an enclosing clutch member on one shaft; an electromag neticbody on the other shaft; a plurality o: superposed friction members; onegroup 0: said friction members being secured to sai( body, an alternategroup of friction mem bers secured to said enclosing clutch member afriction member pressing armature movably located between said enclosingclutcl'. member and the magnet body and adapted tc be attracted by saidmagnet body to close tlu friction members and resilient means entirelyenclosed within said enclosing clutch member for permitting the frictionmembers ,tc separate when the armature is released by the magnet body,said resilient means acting immediately between said magnet body andsaid armature in opposite directions and upon the armature and the bodyonly.-

4. The combination in a shaft clutch, comprising, with a pair of shafts,an enclosing clutch member on one shaft; an'electromagnetic body on theother shaft; a pluralityof superposed friction members; one group .of

"said armature in opposite upon the armature and the body only.

said friction members being secured to said body, an alternate group offriction members secured to said enclosing clutch member; a frictionmember pressing armature movably located between said enclosing clutchmember and the ma etbody and adapted to be attracted 'by sald ma netbody to close the friction members an resilient means between the magnetbody and the armature and entirely enclosed within said enclosing clutchmember for permitting the friction members to separate when the armatureis released by the magnet body, said resilient means acting immediatelybetween said ma net-bodyan 5. The combination in a shaft clutch,comprising, with a pair of shafts, an enclosing clutch member on oneshaft; an electromagnetic body on the other shaft; a plurality ofsuperposed friction members; one group" of said friction members beingsecured to said electromagnetic body, an alternate group of frictionmembers being secured to said enclosing clutch member; a friction memberpressing armature movably located between said enclosing clutch memberand the magnet body and adapted to be attracted by said electromagneticbody to close the frict1on members, and a single set of uniform meanscoacting with said magnet body and said movable armature only, saidmeans being without any immediate action upon said friction members andbeing entirely enclosed within said enclosing clutch member forpermitting the friction members to separate {)vhan the armature isreleased by the magnet Signed at New York, in the county of New York andState of New York, this 19th day of April A. D. 1927.

BRUNO WITTKUHNS.

irections and

